1-propanol is considered a primary alcohol, because the hydroxyl group (-OH) is attached to the first carbon atom in the chain.  It has the chemical formula of CH3CH2CH2OH.  1-propanol is an organic compound, which means it has mostly as its formula atoms of carbon and hydrogen.  Due to the fact it has the hydroxyl group and it is a chain of only three carbons, it is somewhat miscible with water, being able to form a solution as a solvent in water.  A secondary alcohol would have the hydroxyl group attached to the second carbon atom, while a tertiary alcohol would have the hydroxyl group attached to the the third carbon atom.  Alcohols that have longer carbon chains lose their miscibility property with water, as the predominating length of the carbon chain and its organic properties dominate the physical attributes of the molecule.